Index: tools/lld/COFF/Writer.cpp
===================================================================
--- tools/lld/COFF/Writer.cpp
+++ tools/lld/COFF/Writer.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/FileOutputBuffer.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Parallel.h"
 #include "llvm/Support/RandomNumberGenerator.h"
 #include <algorithm>
@@ -177,6 +178,9 @@
   // by the loader.
   if (Header.SizeOfRawData == 0)
     return;
+
+  // It is possible that this assignment could cause an overflow of the u32,
+  // but that should be caught by the FileSize check in OutputSection::run().
   Header.PointerToRawData = Off;
 }
 
@@ -295,6 +299,11 @@
   setSectionPermissions();
   createSymbolAndStringTable();
 
+  if (FileSize > UINT32_MAX)
+    fatal(formatv(
+        "image size ({0}) exceeds maximum allowable size ({1})",
+        FileSize, UINT32_MAX));
+
   // We must do this before opening the output file, as it depends on being able
   // to read the contents of the existing output file.
   PreviousBuildId = loadExistingBuildId(Config->OutputFile);
@@ -571,10 +580,8 @@
   if (OutputSymtab.empty() && Strtab.empty())
     return;
 
-  OutputSection *LastSection = OutputSections.back();
   // We position the symbol table to be adjacent to the end of the last section.
-  uint64_t FileOff = LastSection->getFileOff() +
-                     alignTo(LastSection->getRawSize(), SectorSize);
+  uint64_t FileOff = FileSize;
   PointerToSymbolTable = FileOff;
   FileOff += OutputSymtab.size() * sizeof(coff_symbol16);
   FileOff += 4 + Strtab.size();
@@ -590,7 +597,7 @@
   SizeOfHeaders +=
       Config->is64() ? sizeof(pe32plus_header) : sizeof(pe32_header);
   SizeOfHeaders = alignTo(SizeOfHeaders, SectorSize);
-  uint64_t RVA = 0x1000; // The first page is kept unmapped.
+  uint64_t RVA = PageSize; // The first page is kept unmapped.
   FileSize = SizeOfHeaders;
   // Move DISCARDABLE (or non-memory-mapped) sections to the end of file because
   // the loader cannot handle holes.